while(1)
	{
	if(HIGH==digitalRead(2)){
	delay(50);
	if(HIGH==digitalRead(2))
		break;
		
	}
	}

//延时去抖
if((120<keyVal)&&(keyVal<140))
	{
	delay(10);
	keyVal=analogRead(0);
	if((120<keyVal))&&(keyVal<140)
		{lcd.clear();
		lcd.setCursor(0,0);
		lcd.print("hello,Arduino!");
		}
		}
else  if((300<keyVal)&&(keyVal<310))
		{
		delay(10);
		keyVal=analogRead(0);
		if((keyVal<310)&&(300<keyVal))
			{lcd.clear();
			lcd.setCursor(0,1);
			lcd.print("hello,Arduino!")
			}
		}	

